Laser illumination system with closely spaced beams

Abstract

Techniques are provided for laser illumination employing closely spaced laser beams. A system implementing the techniques according to an embodiment includes a semi-cylindrical optical block comprising a curved surface and a planar surface. The system further includes two laser sources configured to direct first and second laser beams to the curved surface, such that the first laser beam enters and exits the block parallel to and offset from the planar surface by a selected translation distance, and the second laser beam enters the block at a critical angle relative to the planar surface. The critical angle is associated with total internal reflection of the second laser beam along the planar surface, such that the second laser beam exits the block parallel to, and separated from, the first laser beam exiting the optical block. The separation of the exiting first and second laser beams is controlled by the selected translation distance.

What is claimed is: 
     
       1. A laser illumination system comprising:
 a semi-cylindrical refractive optical block, the optical block including a curved surface and a planar surface; 
 a first laser source to generate a first laser beam directed to the curved surface, wherein the first laser beam enters and exits the optical block parallel to the planar surface and offset from the planar surface; and 
 a second laser source to generate a second laser beam directed to the curved surface, wherein the second laser beam enters the optical block at a critical angle relative to the planar surface, the critical angle causing total internal reflection of the second laser beam along the planar surface, such that the second laser beam exits the optical block parallel to, and separated from, the first laser beam exiting from the optical block, the separation based on the offset of the first laser beam from the planar surface. 
 
     
     
       2. The system of  claim 1 , further comprising a mounting mechanism configurable to adjust the position of the first laser source causing the offset of the first laser beam from the planar surface to be adjusted such that the separation is a desired separation. 
     
     
       3. The system of  claim 2 , wherein the desired separation is less than a diameter of the first laser beam or the second laser beam. 
     
     
       4. The system of  claim 1 , further comprising a first diverging lens to diverge the first laser beam exiting the optical block and a second diverging lens to diverge the second laser beam exiting the optical block. 
     
     
       5. The system of  claim 4 , wherein the divergence is in the range of 15 to 35 degrees. 
     
     
       6. The system of  claim 4 , wherein the diverged first laser beam illuminates a first surface area and the diverged second laser beam illuminates a second surface area, the first surface area overlapping the second surface area by an overlap percentage in the range of zero to 100 percent. 
     
     
       7. The system of  claim 4 , wherein the first surface area and the second surface area are both associated with a length dimension and a width dimension, the length dimension in the range of 0.5 meters to 1.0 meters, and the width dimension in the range of 1.0 meters to 2.0 meters. 
     
     
       8. A method for providing laser illumination, the method comprising:
 directing a first laser beam to a curved surface of a semi-cylindrical refractive optical block, the optical block comprising the curved surface and a planar surface, wherein the first laser beam enters and exits the optical block parallel to the planar surface and offset from the planar surface; and 
 directing a second laser beam to the curved surface, wherein the second laser beam enters the optical block at a critical angle relative to the planar surface, the critical angle causing total internal reflection of the second laser beam along the planar surface, such that the second laser beam exits the optical block parallel to, and separated from, the first laser beam exiting from the optical block, the separation based on the offset of the first laser beam from the planar surface. 
 
     
     
       9. The method of  claim 8 , further comprising adjusting the offset of the first laser beam from the planar surface such that the separation is a desired separation. 
     
     
       10. The method of  claim 9 , wherein the desired separation is less than a diameter of the first laser beam or the second laser beam.